1. Field of the Invention
The present invention relates to a headlight device for a vehicle such as an automobile and the like and, particularly to a tilting device of the headlight for changing the direction of the light beam.
2. Description of Prior Art (FIG. 14)
Various headlights have been proposed and utilized, and it is usually required that the light beam of the headlight can be directed to a desired direction so as to improve the safety in the traffic.
For end, a member defining the direction of the light beam such as a headlight unit or a reflector and the like is mounted tiltably on a supporting member such as a member secured to the chasis of the vehicle, and a tilting or inclinating mechanism is provided for tilting the tiltable member as desired. The headlight unit generally consists of a reflector and a light source which are disposed in a lamp space defined by a lamp body and a lens covering the front opening of the lamp body.
In adjusting the direction of the light beam, there has been adopted two steps, i.e. the initial aiming adjustment which is performed when the headlight is mounted on the vehicle and prior to usage or on the initial inspection process, and a leveling adjustment which is performed to compensate the change in the load of the vehicle such as passengers or the loading of the vehicle and the like. The change in the load of the vehicle usually changes the direction of the light beam in the vertical direction. The initial aiming adjustment is usually performed manually, and the leveling adjustment is usually performed through a remote controlled actuating mechanism.
The aiming adjustment is usually effected to change the direction of the light beam horizontally and vertically and the adjusting mechanism are provided at two separate points, and the actuating mechanism for the leveling adjustment is usually provided on the aiming adjusting point for effecting the adjustment in the vertical direction. Some prior art tilting device integrally comprises the aiming adjust mechanism and the leveling adjust mechanism.
FIG. 14 shows schematically a prior art headlight device a having the tilting device of above mentioned type. Shown at b is the tilting device, at c is a casing secured to the inner surface of the rear wall of a lamp housing d, at e is a worm wheel rotatably supported on the casing c and not being displaceable in the axial direction, at f is a tubular member displaceable in the axial direction and threadingly engaging with the worm wheel e, at h is an adjust rod having screw threads along the main portion of the length for engaging with the tubular member f. A ball i is formed on the front end of the rod h, and the rear end of the rod h projects from the rear surface of the lamp housing d. Shown at k is a headlight unit tiltably supported on the lamp housing d. A receptacle 1 is supported on the lower end for engaging with the ball i to constitute a ball joint.
A drive unit including a motor, worm gears and the like (not shown) is disposed in the casing c to rotate the worm wheel e.
In the initial aiming adjustment, the rod h is rotated relative to the tubular member f so as to be threaded into or out thereof. The rod h moves axially, and the headlight unit k tilts in the vertical direction and the direction of the light beam is adjusted.
When the worm wheel e is rotated by the drive unit through the remote control device the rod h moves together with the tubular member f and a similar adjustment is performed, which is the leveling adjustment.
In the vehicle headlight device it is essential to perform the initial aiming adjustment, but the mechanism for the leveling adjustment is not essential.
According to the prior art tilting device b, it is convenient that the initial aiming adjusting means and the leveling adjusting means are provided integrally. However, it is difficult to omit the leveling adjusting means, and the lamp housing d is exclusively used to the tilting device b. Thus, it is required to provide a separate aiming adjusting means for a headlight device wherein the leveling adjustment is not required. In such case it is required to prepare various types of tilting devices which increases the number of parts, and tools and jigs and the like for producing the same, thereby increasing the cost.
An object of the invention is to solve the problems above mentioned.